Re: mmotm 2020-05-13-20-30 uploaded (objtool warnings)

From: Peter Zijlstra
Date: Fri May 29 2020 - 12:57:05 EST


On Fri, May 29, 2020 at 11:50:11AM -0500, Josh Poimboeuf wrote:
> The nested likelys seem like overkill anyway -- user_access_begin() is
> __always_inline and it already has unlikely(), which should be
> propagated.
>
> So just remove the outer likelys?

That fixes it. Ack!

> diff --git a/arch/x86/lib/csum-wrappers_64.c b/arch/x86/lib/csum-wrappers_64.c
> index a12b8629206d..ee63d7576fd2 100644
> --- a/arch/x86/lib/csum-wrappers_64.c
> +++ b/arch/x86/lib/csum-wrappers_64.c
> @@ -27,7 +27,7 @@ csum_and_copy_from_user(const void __user *src, void *dst,
> might_sleep();
> *errp = 0;
>
> - if (!likely(user_access_begin(src, len)))
> + if (!user_access_begin(src, len))
> goto out_err;
>
> /*
> @@ -89,7 +89,7 @@ csum_and_copy_to_user(const void *src, void __user *dst,
>
> might_sleep();
>
> - if (unlikely(!user_access_begin(dst, len))) {
> + if (!user_access_begin(dst, len)) {
> *errp = -EFAULT;
> return 0;
> }
>